PVP Games Signaling Server v2.0

Endpoints:
- GET /health - Health check
- GET /ice-servers - Get TURN/STUN configuration
- GET /api/room/:id - Room info
- WS /ws?room=:id&role=host|guest - WebSocket connection

Features:
- WebRTC signaling for P2P connections
- WebSocket relay fallback
- Hibernation API for efficiency
- Location-aware DO placement